The present invention generally pertains to antenna systems and is particularly directed to an improvement in multi-spectral detection systems.
A multi-spectral detection system may be used for detecting radiation in diverse portions of the electromagnetic spectrum. The electromagnetic spectrum includes both radio frequency radiation and electro-optical radiation. Radio frequency radiation includes microwave, millimeter wave and sub-millimeter wave radiation. Electro-optical radiation includes infrared, visible and ultraviolet light.
Radio frequency and electro-optical radiation detection systems have been employed to detect the presence of and/or track moving and stationary objects and to measure some of their characteristics. The uses of these systems range from the detection of military targets to the spectral analysis of molten metals.
A particular implementation for a multi-spectral detection system is in a miniature weapon system, for enabling operation in adverse weather (e.g., fog, haze, rain). Such a system provides comprehensive false target discrimination by employing two or more radiation detectors operating in diverse portions of the electromagnetic spectrum. The detectors generate unique target signature data which are correlated to provide a target/no-target decision with a high confidence level. A specific embodiment is a combined millimeter wave/infrared detection system.
Both active millimeter wave detection systems and passive infrared detection systems perform well against vehicular ground targets under some adverse weather conditions, and each can provide limited false target rejection capability. The active millimeter wave detection system detects metallic objects by means of reflection and backscatter. It utilizes a relatively wide antenna beam which is effective during a wide area target search. It also can employ range and/or moving target indication circuits to enhance target discrimination. Moreover, millimeter wave radiation can penetrate fog and atmospheric particulates with little attenuation.
The passive infrared detection system detects objects by means of inherent temperature differentials. It utilizes a relatively narrow beam for fine tracking and it can employ multiple frequency bands to provide discrimination against flares, burning vehicles, and sunglints. Infrared radiation can penetrate chaff and moderate rain efficiently.
It is an object of the present invention to provide an improved multi-spectral detection system that will enhance the achievement of high probability acquisition and accurate tracking of vehicular ground targets under most adverse weather conditions, while at the same time providing comprehensive false target rejection capability.